On Thu, 26 Feb 2015, Satish Balay wrote: > On Thu, 26 Feb 2015, Nathan Collier wrote: > > > Ok, so I am not sure I got all that, but here goes some more information > > (attached log). > > > > No packages / master > > > > [nate@titan] time python no_packages.py > > ... > > real 14m32.169s > > user 1m51.527s > > sys 3m40.734s > > > > [nate@titan] time make all > > ... > > real 15m56.004s > > user 8m8.971s > > sys 52m42.734s > > BTW: This number for 'make all' looks bizzare [or I don't know how to > interpret it]. > > - 'sys' time is 52m? > - 'user' time is 8m - but 'real' is 15m - so its not a parallel build? > But configure sets 'MAKE_NP = 24' (with gnumake build). > > Perhaps its all intel compiler license server overhead? :)
Ah - I was misreading. 'sys' is cumilative time across all procs. So speedup factor with parallel build is something like: (user+sys)/real - which is 3.8 The 'sys' time - which is 6.5 times more than 'user' time - this is puzzling. Perhaps this happend if the machine is actively used by many users? For Mira the numbers are: real 1m49.837s user 26m1.417s sys 9m11.808s with (user+sys)/real = 19.2 [with MAKE_NP=32] - and the 'sys' time is a small fraction of user time. Satish
